X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=tfcrypt.c;h=4724c0fab024cf88ab10fa8492dfce05c0cbeb76;hb=e0d3bb48cd0cd079f9d1bd5555a52f450db452ac;hp=8608cf16011399202e66f08b8855211c6368a56e;hpb=429747d78e7e60b3dc44fd8b23f1626c386663e0;p=tfcrypt.git

diff --git a/tfcrypt.c b/tfcrypt.c
index 8608cf1..4724c0f 100644
--- a/tfcrypt.c
+++ b/tfcrypt.c
@@ -171,6 +171,10 @@ int main(int argc, char **argv)
 					catch_all_errors = YES;
 					break;
 				}
+				if (!strcmp(optarg, "xseek")) {
+					ignore_seek_errors = YES;
+					break;
+				}
 				if (!strcmp(optarg, "exit"))
 					error_action = TFC_ERRACT_EXIT;
 				else if (!strncmp(optarg, "cont", 4))
@@ -328,13 +332,25 @@ int main(int argc, char **argv)
 						s += 5;
 						maxkeylen = tfc_humanfsize(s, &stoi);
 						if (!str_empty(stoi)) {
-							maxkeylen = (size_t)tfc_fnamesize(s, YES);
-							maxkeylen = (size_t)tfc_modifysize((tfc_fsize)maxkeylen, strchr(s, ':'));
+							maxkeylen = tfc_fnamesize(s, YES);
+							maxkeylen = tfc_modifysize(maxkeylen, strchr(s, ':'));
 							if (maxkeylen == NOSIZE)
 								xerror(NO, YES, YES,
 								"%s: invalid key length value", s);
 						}
-						else maxkeylen = (size_t)tfc_modifysize((tfc_fsize)maxkeylen, strchr(s, ':'));
+						else maxkeylen = tfc_modifysize(maxkeylen, strchr(s, ':'));
+					}
+					else if (!strncmp(s, "okey", 4) && *(s+4) == '=') {
+						s += 5;
+						keyoffset = tfc_humanfsize(s, &stoi);
+						if (!str_empty(stoi)) {
+							keyoffset = tfc_fnamesize(s, YES);
+							keyoffset = tfc_modifysize(keyoffset, strchr(s, ':'));
+							if (keyoffset == NOFSIZE)
+								xerror(NO, YES, YES,
+								"%s: invalid key offset value", s);
+						}
+						else keyoffset = tfc_modifysize(keyoffset, strchr(s, ':'));
 					}
 					else if (!strncmp(s, "xctr", 4) && *(s+4) == '=') {
 						s += 5;
@@ -683,7 +699,7 @@ _ctrskip1:
 		if (counter_opt == TFC_CTR_HEAD && ctr_mode != TFC_MODE_ECB)
 			iseek += ctrsz;
 		if (lseek(sfd, iseek, SEEK_SET) == -1)
-			xerror(YES, NO, NO, "%s: seek failed", srcfname);
+			xerror(ignore_seek_errors, NO, NO, "%s: seek failed", srcfname);
 	}
 
 	if (ctr_mode == TFC_MODE_PLAIN) goto _plain;
@@ -814,7 +830,7 @@ _pwdagain:	memset(&getps, 0, sizeof(struct getpasswd_state));
 		memset(pwdagain, 0, sizeof(pwdagain));
 	}
 	else {
-		if (skeinfd(key, TFC_KEY_BITS, mackey_opt ? mackey : NULL, kfd, maxkeylen) != YES)
+		if (skeinfd(key, TFC_KEY_BITS, mackey_opt ? mackey : NULL, kfd, keyoffset, maxkeylen) != YES)
 			xerror(NO, NO, YES, "hashing key");
 	}
 
@@ -887,11 +903,12 @@ _xts2genkey:	if (xwrite(krfd, pblk, TF_FROM_BITS(TFC_KEY_BITS)) == NOSIZE) xerro
 		if (!tweakf) skein(key+TF_FROM_BITS(TF_MAX_BITS)+TF_SIZE_UNIT, 2*TF_UNIT_BITS, NULL, key, TF_FROM_BITS(TFC_KEY_BITS));
 		tf_key_tweak_compat(key);
 	}
-	if (ctr_mode == TFC_MODE_STREAM) tfe_init_iv(&tfe, key, ctr);
 	if (ctr_mode == TFC_MODE_ECB) goto _ctrskip2;
 	tfc_data_to_words64(&iseek_blocks, sizeof(iseek_blocks));
 	tf_ctr_set(ctr, &iseek_blocks, sizeof(iseek_blocks));
 
+	if (ctr_mode == TFC_MODE_STREAM) tfe_init_iv(&tfe, key, ctr);
+
 	switch (counter_opt) {
 		case TFC_CTR_SHOW:
 			switch (do_outfmt) {
@@ -926,7 +943,7 @@ _plain:
 
 	if (oseek) {
 		if (lseek(dfd, oseek, SEEK_SET) == -1)
-			xerror(YES, NO, NO, "%s: seek failed", dstfname);
+			xerror(ignore_seek_errors, NO, NO, "%s: seek failed", dstfname);
 	}
 
 	for (x = 1; x < NSIG; x++) signal(x, SIG_IGN);